Captain Sam's:
Today was almost similar to yesterday. With a total of 51 birds, only 4 of those birds were recaptures. A unique catch of the day was Captain Sam's getting an Eastern Kingbird during our first net run. It was really fun to finally catch one! Common Yellowthroats were our highest catch with a total of 35 out of the 47 newly banded birds. It's the start of our first waves of Common Yellowthroats, but over the years it's a slow decrease of the total number of Common Yellowthroats we catch. Check out this chart below here to see how each year differs from 2012 to 2019. The 2-month long catch of Common Yellowthroats are still the same each year but the numbers have been decreasing.
My next topic is aging White-eyed Vireos! Check out the 2 images below. You can see that the first image, this White-eyed Vireo has a nice bright eye and overall great color contrast. At first glance, one may think that this is an adult bird. Looking closer, in the second image you can start to see what we are looking at when aging birds.
*Note* not all birds will have the same molt and can vary from species to individuals
When looking at this image below, you can see I have labeled each feather on the wing. Each number has a letter in front of them, S- meaning Secondaries and P- meaning Primaries. For a White-eyed Vireo, they have 10 primaries and 9 secondaries as listed below. When holding a bird and looking at the feather, we look for any new feathers that are replaced and compare them to older feathers that have not been replaced. I made a cheat view in this image by color coding my feathers to indicate old feathers to new growth. New feathers are labeled in Red, while the old feathers are labeled in Blue.
This bird has started an eccentric molt which means this bird has started only part of the primary feather molt. This starts at p5 to p10. You can also see that s9 to s5 have also been replaced. These new feathers give off a cleaner and more darker feather contrast than the older feathers.
Thanks for checking out this blog and until next time,
Kristin
Little Bear:
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| Sunrise at Little Bear. Photo by Ben Stalheim |
Expectations were tempered today at Little Bear, but upon feeling the lower humidity and cool breeze, all of us felt some optimism about the day of banding. Unfortunately, we didn't get a big haul of Common Yellowthroats like Captain Sam's did, but we were able to catch a few new species for the Little Bear site this season. Most interestingly, a young Eastern Screech-Owl was in a net on our first check. Nate carefully extracted it and we all worked to band, age, and sex the bird. When looking to age the owl, we took a look at the patterning of its outer primary coverts. On hatch-year birds, there is distinct white spotting separated by the typical rusty brown. However, if this bird had undergone more than its preformative molt, we would see a white band connecting these spots in the coverts. Our bird had white spots without the white band connecting them, and we felt confident this was a hatch-year bird. To sex our owl, we go off wing and tail measurements. However, these can sometimes overlap, and in the case of our bird, not lead to a definitive answer. So we simply left it as sex unknown. Josh snagged some pretty great photos and we let this adorable predator back into the world.
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| Hatch-year Eastern Screech-Owl. Photo by Josh Lefever |
The other bird we hadn't yet caught this year? A Yellow-breasted Chat! Things had started to slow down, when miraculously, Josh brought back a good haul of birds. Including, the amazing and brightly colored Chat. Yellow-breasted Chats can do eccentric molts as hatch-year birds, which is a good way to quickly determine the age. In our bird, it was subtle, but the Chat had replaced its outer primaries (P4-9), but not P1-3. In a definitive molt cycle, the bird would start at P1 and replace all its flight feathers symmetrically. However, with the eccentric molt, it skips some of its inner primaries and outer secondaries and chooses to replace blocks of feathers in a seemingly "out of order" way, despite that there is nothing out of order about it. This Chat had also replaced its inner secondaries (S6-9) and not S1-5, again creating a block of new formative feathers contrasting with its retained juvenile ones.
Kristin explains it much better above and has excellent photos to display this pattern, but it is a fascinating strategy and one that helps us to age birds in the hand.
Although we did catch only 7 Common Yellowthroats, we were lucky to start seeing some unique-looking hatch-year males growing in their characteristic black masks.
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| Hatch-year Male Common Yellowthroat. Photo by Ben Stalheim |
-Ben
| Species | Captain Sam's | Little Bear | ||
|---|---|---|---|---|
| New | Recaps | New | Recaps | |
Eastern Screech Owl | - | - | 1 | - |
Downy Woodpecker | - | 1 | - | - |
Eastern Kingbird | 1 | - | - | - |
Red-eyed Vireo | 2 | - | - | - |
Carolina Wren | - | 1 | - | - |
Yellow-breasted Chat | - | - | 1 | - |
Ovenbird | 1 | - | - | - |
Northern Waterthrush | 2 | - | 3 | - |
Black-and-white Warbler | 1 | - | - | - |
Common Yellowthroat | 34 | - | 7 | - |
American Redstart | 2 | - | 1 | - |
Yellow Warbler | 1 | - | 3 | - |
Northern Cardinal | 1 | - | - | 1 |
Painted Bunting | 1 | 2 | 2 | 1 |
| Today's Banding Stats | Captain Sam's | Little Bear | TOTAL |
|---|---|---|---|
| # Birds Banded | 47 | 18 | 55 |
| # of Recaptures | 4 | 2 | 6 |
| # of Species | 10 | 8 | 12 |
| Effort (net-hours) | 175.5 | 109.5 | 285 |
| Capture Rate (birds/100 net-hours) | 29.1 | 18.3 | 21.4 |
| # of Nets | 30 | 23 | - |
| 2021 Fall Cumulative Banding Stats | Captain Sam's | Little Bear | TOTAL |
|---|---|---|---|
| # Birds Banded | 413 | 248 | 661 |
| # of Recaptures | 116 | 42 | 158 |
| # of Species | 37 | 30 | 44 |
| Effort (net-hours) | 2,710.5 | 1,478.4 | 4,188.9 |
| Capture Rate (birds/100 net-hours) | 19.5 | 19.6 | 19.55 |
| # of Days | 20 | 15 | - |
Banding Staff
Kristin Attinger (CS)
Nate Watkins (LB)
Kandace Glanville (CS)
Ben Stalheim (LB)
Josh Lefever (LB)
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